The Pulitzer Prize winner died at a hospice in Rockville, Md. The cause of death was pancreatic cancer, family friend Martin Tolchin said.

Safire spent more than 30 years writing on the Op-Ed page of The New York Times. In his “On Language” column in The New York Times Magazine and more than a dozen books, Safire traced the origins of words and everyday phrases such as “straw man,” “under the bus” and “the proof is in the pudding.”

New York Times Co. Chairman Arthur Sulzberger Jr. said in a statement: “For decades, Bill’s columns on The Times’s Op-Ed Page and in our Sunday Magazine delighted our readers with his insightful political commentary, his thoughtful analysis of our national discourse and, of course, his wonderful sermons on the use and abuse of language. Bill will be greatly missed.”

Michael Oreskes, senior managing editor of The Associated Press, who served as a correspondent and Washington bureau chief of the Times during Safire’s years as a columnist, said the conservative writer was a mentor and friend to a generation of Washington journalists of all political persuasions.

“He believed in the values of journalism — of ferreting out the truth and holding leaders to account, Republicans and Democrats,” Oreskes said. “Above all, he loved to encourage his colleagues to break a good story and raise hell.”

Safire penned more than 3,000 columns, aggressively defending civil liberties and Israel while tangling with political figures. Bill Clinton famously wanted to punch the curmudgeonly columnist in the nose after Safire called his wife “a congenital liar.”

Safire’s assistant Rosemary Shields said: “Not only was he brilliant in language and assessing the nuances of politics, he was a kind and funny boss who gave lots of credit to others.”

As a speechwriter in the Nixon White House, Safire penned Vice President Spiro Agnew’s famous phrase, “nattering nabobs of negativism,” a tongue-in-cheek alliteration that Safire claimed was directed not at the press but at Vietnam defeatists.

Safire also wrote several novels and served as chairman of the Dana Foundation, a philanthropy that supports brain science, immunology and arts education.

Along with George Will and William F. Buckley Jr., Safire’s smooth prose helped make conservatism respectable in the 1970s, paving the way for the Reagan Revolution.

Safire was a pioneer of opinionated reporting. His columns were often filled with sources from Washington and the Middle East, making them must-reads for Beltway insiders.

Author Eric Alterman, in his 1999 book “Sound and Fury: The Making of the Punditocracy,” called Safire an institution unto himself.

“Few insiders doubt that William Safire is the most influential and respected pundit alive,” Alterman wrote.

Safire’s scathing columns on the Carter White House budget director Bert Lance’s financial affairs won him the Pulitzer Prize for commentary in 1978; in 1995 Safire was named to the Pulitzer board.

Critics said Safire made loose accusations trumpeting various “scandals” by the Clintons that were never borne out by the facts.

“Like a pioneering blogger, Safire years ago started grabbing bits of information and wrapping them in the tightest partisan, what-if spin possible,” Eric Boehlert wrote in the Web site Salon in 2004. “When the accusation unraveled, he’d simply ignore the thud of his charges hitting the floor.”

From 2001 to 2003, Safire also published several columns pressing the case that Saddam Hussein was linked to the Sept. 11 attacks, calling it an “undisputed fact” that hijacker Mohamed Atta met with a senior Iraqi intelligence official in Prague in April 2001. The 9/11 commission said that meeting never happened.

Safire’s pun-filled “On Language” column exploring the foibles and abuses of the English language was far less controversial, winning him more admirers across the political spectrum.

Safire lived in the Washington suburb of Chevy Chase, Md., with his wife, Helene, a British-born jewelry designer; they had a son and a daughter.

Safire, born Dec. 17, 1929, to a Jewish family in New York City, was the youngest of three boys. He attended Syracuse University but dropped out after two years to work as a legman for a Republican political strategist and publicist Tex McCrary, who had a column in the New York Herald Tribune.

Safire started writing speeches for Nixon in 1965 and followed him to the White House. He left shortly before the Watergate break-in erupted into a full-fledged scandal.